1. Field of The Invention
This invention relates to means for measuring the overstress in pipe pilings and the like, for achieving such at any location in such pipe pilings. This invention further relates to means for remotely and automatically indicating and recording such measurements.
2. Prior Art
U.S. Pat. No. 1,890,607 discloses a depth indicator and inclinometer which includes a lower cable and a hermetically sealed shell. A plurality of wheels anchored on the shell and contacting the interior of a well casing or drill pipe. A travelling tape recording means located in the shell to measure the depth.
U.S. Pat. No. 2,030,244 teaches a calipering device for detecting and measuring variations in the inside diameter of a cylindrical tube. Arms which are adjusted to engage the side of the wall are mounted on the top end of the device. Spring-extended special arms are mounted on the lower end of the device. Indicating means are coordinated with the movement of the special arms so as to measure such movement and indicate such at above ground level. U.S. Pat. No. 2,074,753 teaches a gauge for indicating a irregularity in boiler or heater tubes, such irregularity indicating a weakened section in the tube. The gauge includes a head which a series of plunges slidably mounted through the side thereof in a radial manner. As the head travels inside the tube, a maximum degree of in and out movement of each of said plungers is electrically indicated at a remote station. This is done by means on a contact on the moving plunger meeting a positioned contact (one for inwards movement and one for outwards movement), which closes the appropriate electrical circuit and indicates a pipe deformity (in or out) of a certain magnitude or larger. The head is located on a rod and has pre-usage adjustable guides. Also, several guide disks are located on the rod.
U.S. Pat. No. 2,121,614 discloses a cylinder gauge for measuring and recording the minimum and maximum internal diameters of cylinders and tubes (such as, tubular oil stills). A series of radial floating wheels mounted on arms are radially located on each end of the cylinder and serve the purpose of aligning the cylinder. A series of radial floating recording arms, outwardly pressured, are located in the middle portion of the cylinder. A rotably horizontally mounted disc inside of the cylinder contains a disc of paper. The disc is mounted on a collar which contains ratchet teeth around its diameter. The mechanism allows remote manual manipulations that result in on-the-spot recordings of the maximum and minimum internal diameter of a tube at a particular location.
U.S. Pat. No. 2,497,990 teaches an apparatus for logging boreholes. The apparatus includes a body upon which are mounted two spring-outwardly pressurized arms -- a rotary knife blade mounted on the end of each arm. The knife blade pierces the mud layer in the borehole. Curved sections are mounted on arms that are outwardly-faced from the body. The arms are electrically connected to a surface-located recording galvanometer which records the resistance of the particular circuit being measured at that time -- this allows measurement of the thickness of the mud cake on the hole wall between the two appropriate arms.
U.S. Pat. No. 2,518,663 teaches a tube calipering and recording device for measuring and recording variations in the internal surface wear of pipes and the like. The device is completely self-contained and mechanically operated and does not require the use of insulated electrical cables communicating with the surface -- this means that results cannot be obtained until the device is pulled back up to the surface and opened. The device contains a plurality of wall feelers that are sequentially positioned to by a recording means that is driven by a wheel which contacts the tube wall. Only the deepest pit in the tube wall can be measured by the devices at a particular depth.
U.S. Pat. No. 2,527,170 discloses an apparatus for detecting corrosion of a casing or tubing -- such corrosion usually occurs on the outside of the casing. The corrosion causes a decrease in the thickness of the casing wall, which produces a readily distinguishable signal on a recording of a magnetic scan. The apparatus has a rotating scanning devise which includes a permanent magnet on one end of a rotating arm, a magnetic material on the other end and a coil wound around the latter, and has a surface located recorder (pen type or galvanometer type). The scanning device is driven by a battery-driven motor located in the apparatus. The apparatus contains a self-centering arrangement which involves at least three wheels on arms that are spring-loaded by a centrally located spring. A disadvantage of the apparatus appears to be that the scanning device must be rotated with little clearance to the casing wall, which of course means that many different apparatus having the appropriate diameter are required in order to measure casings having not too wide a difference in internal circumferences.
U.S. Pat. No. 2,578,236 teaches a tubing calipering device which includes spring-loaded wheel drive means. Particular means are taught for recording the deepest pit in tubing which is located by a rotating arm contacting the tubing wall. The device includes a self-contained stylus-chart arrangement.
U.S Pat. No. 2,656,613 teaches an apparatus for calipering well bores -- it is used for measurement of bores which may have relatively wide variations in measurements. The apparatus utilizes a plurality of arms which follow the bore wall. The arms control a strain gauge which sends out a frequency which is in direct proporation to the average position of the plurality of movable arms. U.S. Pat. No. 2,680,913 discloses a device for determining the shape and diameter of well bores. The device contains a plurality of releaseable arms that are spring-forced outwardly against the bore wall. A clock mechanism to drive a tubular chart affords a stylus record of diameter for each arm as the device is removed from the bore.
U.S. Pat. No. 2,708,316 teaches a calipering and recording device for use in tubes. The device has a plurality of wheels that are pressured against the bore wall in order to adjust to different diametered bores and to prevent rotation of the device during measurement. The device contains a series of feelers which contact the bore wall. The feeler movement causes reciprocative movement between a stylus and a chart which records in effect the feeler value and movement. The device has wheel drive means.
U.S. Pat. No. 2,719,361 teaches an apparatus for calipering a well bore as it is being drilled. The end of the apparatus contains a series of retractable outwardly-forced arms. Below the apparatus is the drill bit. Along the same lines, see U.S. Pat. No. 2,719,363.
U.S. Pat. No. 2,815,578 discloses an apparatus, including telemetering system, for measuring and recording dimensions, temperature, pressure or other variable phsyical conditions in well boreholes. The apparatus contains four arms (contacts) which ride on the borehole wall. The measurements are made using a particular rotating helical contact, means for speed synchronization and surface recording. U.S. Pat. No. 2,973,583 discloses a tube calipering device which contains two sets of wheels in contact with the wall of the tubular conduit. The device has a series of spring-loaded arms which engage the wall in order to locate and measure irregularities in the wall such as those caused by corrosion or resulting from mechanical damage of tubes used in furnaces and the like. The device contains some very narrow and specific limiting features.
U.S. Pat. No. 3,685,158 teaches an apparatus for making measurements in a well bore. The apparatus contains at least one pair of specific, articulated wall-engaging members.
Attention is also drawn to U.S. Pat. No. 770,978.
The prior art does not teach or suggest a device, which can be lowered into a driven piling, that detects overstress in a pipe piling.